_ is not defined custom yeoman generator - yeoman

Question

I am working on my first custom Yeoman Generator and have hit a snag. I am getting the error of _ is not defined when the generator is creating the package.json file. The error is in reference to
1| {
>> 2| "name": "<%= _.slugify(appName) %>",
3| "version": "0.0.1",
4| "description": "<%= appDescription %>",
5| "author": "<%= authorName %>",
Here is my index.js file
'use strict';
var _ = require('underscore.string');
var generators = require('yeoman-generator');
var chalk = require('chalk');
var yosay = require('yosay');
module.exports = generators.Base.extend({
prompting: function () {
var done = this.async();
// Have Yeoman greet the user.
this.log(yosay(
'Welcome to the ' + chalk.red('\nSMS Boilerplate') + '\n generator!'
));
this.log(chalk.green(
'You\'ll also have the option to use Normalise-css and Modernizr.js \n'
));
this.prompt([{
type: 'input',
name: 'appName',
message: 'Your project name',
default: 'sms-project',
store: true
}, {
type: 'input',
name: 'appDescription',
message: 'Short description of the project...',
default: 'A new SMS project',
store: true
}, {
type: 'input',
name: 'gitUsername',
message: 'What\'s your Github username?',
store: true
}, {
type: 'input',
name: 'authorName',
message: 'What\'s your name (the author)?',
default: '',
store: true
}, {
type: 'confirm',
name: 'includeNormalize',
message: 'Would you like to include Normalize.css?',
default: true
}]).then(function(answers) {
this.props = answers;
this.log('app name', answers.appName);
done();
}.bind(this));
},
writing: {
// Copy the configuration files
config: function() {
this.fs.copyTpl(
this.templatePath('_package.json'),
this.destinationPath('package.json'),
{
appName: _.slugify(this.props.appName),
appDescription : this.props.appDescription,
authorName : this.props.authorName
}
);
this.fs.copyTpl(
this.templatePath('_bower.json'),
this.destinationPath('bower.json'),
{
appName: this.props.appName,
appDescription : this.props.appDescription,
authorName : this.props.authorName,
includeNormalize : this.props.includeNormalize
}
);
this.fs.copy(
this.templatePath('bowerrc'),
this.destinationPath('.bowerrc')
);
},
// Copy Application Files
app: function() {
this.fs.copy(
this.templatePath('scss/_style.scss'),
this.destinationPath('scss/style.scss')
);
this.fs.copy(
this.templatePath('css/_style.css'),
this.destinationPath('css/style.css')
);
this.fs.copy(
this.templatePath('js/_script.js'),
this.destinationPath('js/script.js')
);
this.fs.copyTpl(
this.templatePath('index.html'),
this.destinationPath('index.html'),
{
appName: this.props.appName,
appDescription : this.props.appDescription,
authorName : this.props.authorName
}
);
this.fs.copy(
this.templatePath('_Gruntfile.js'),
this.destinationPath('Gruntfile.js')
);
},
},
//Install Dependencies
install: function() {
this.installDependencies({
bower: true,
npm: true,
callback: function() {
this.spawnCommand('grunt', ['bowerBuild']);
}.bind(this)
});
},
});
I am using Yeoman Generator v 0.23.0 and Node v 4.4.5
Thank you for any help.

Answer 1

underscore wasn't passed inside your template. So when you try to access function on it, it's telling you it's not there.
My suggestion is to preformat your input inside your generator code and only pass strings as template context. It's usually better to keep templates logic less.
Otherwise you can pass it manually this.fs.copyTpl(from, to, {_: _, ...etc})